text:
What's the wisdom of attaching an aircraft lift strut to a wing spar utilizing a single eye bolt vs the common two plate or strap method?
in the enclosed picture are three examples of types I'm speaking of.  In the top picture, the lift struts are attached via a single eye bolt.  The eye bolt is obviously vertical through the wingspar
I looked at the rudimentary engineering drawing elsewhere on this site showing the forces acting on the wing spar, and get that the wingspar is tending to make an S curve.  Let's assume that the wing spar in question has an internal sleeve doubler to effectively increase wall thickness to resist compression and prevent the collapse of the tube.
In the middle drawing, the most common method method. Two straps fore and aft, attached via a bolt horizontally though the spar. I have an elementary understanding that this second, commonplace method puts drilled holes through what I believe is the "neutral axis" of the spar.
finally, the bottom illustration of the "texas parasol" type of fitting.  It shares a commonality with the eye bolt in that there are holes drilled through the compression and tension axis vertically through the spar and attaching a u shaped bracket to the bottom of the spar into which the lift strut is through bolted.  Two holes, albeit smaller in diameter than the single but larger hole of the eye bolt.

welcome to the site! I just rotated the image so it can be read better

@ToddMcLauchlin Please have a look at the tour to find out more on how this site works. I had to reject an edit to John K's answer twice already. Please use comments under the answer instead of edits to ask for clarification.

Vertical bolt = less optimal.  The reason is the tube walls in the 12:00 and 6:00 locations (top and bottom areas) are effectively the primary tension and compression members of the tube, and the 9 - 3:00 areas are the shear zones.
In other words, if the tube was an I beam, you'd be putting holes right in the cap strip flange of the I beam where the tension and compression loads are highest.  You're like the plumber who drills holes in floor joists too close to the edge and severely weakens the joists.
The horizontal bolt is much better because the holes are in the neutral axis of the tube, the middle of the shear zone, and the bolt/nut serve to prevent the tube from ovalizing (squashing flat) under bending load. So the horizontal bolt actually strengthens the tube overall, because the hole has little effect on the upper surface's compression strength and the lower surface's tensile strength, and the bolt and nut support braces the tube against flattening (by preventing the sides from spreading), so the upper and lower surfaces can get closer to their actual stress limit potential.
So the middle picture, pound for pound structure wise, is the best method. However you can do it the other way if you size the material to compensate for the strength lost to the holes at the top and bottom, so either way will work.
And in fact, on something like an ultralight with wire braced wings and a spar supported at multiple points along the span, a designer may find a vertical eye bolt like the top sketch to be the most elegant solution in the greater scheme of things, and it's worth while to do it that way and compensate as required with heavier meat adjacent to the holes than would be needed with a horizontal hole.
But if you tested the single vertical bolt configuration against the single horizontal bolt configuration, with identical hole sizes and material thicknesses, the vertical one would almost certainly fail first.

John K thank you for your reply.  I think I need to post a new question as to how to proceed to address the issues you have identified.

@ToddMcLauchlin you need to find a book on the design of tubes as beam spars.  You need to know how to do the stress analysis to select and size the material, then when you have a design you have to build it and do a static load test on it (set it up upside down on a test fixture and pile on the sand bags) up to the intended load limit to validate the analysis.  That's if you actually intend to bet your life on the structure in the air.  If you don't plan to do all that, don't bother.   Just build a Goat from the free plans available on-line.

Wouldnt the vertical connection also have unwanted bending stresses on the strut from trying to meet the wing at a fixed angle?

The lift strut in his diagram with the vertical bolts still has a pin joint horizontal bolt where the strut connects to the bracket, so deformations in the spar tube under load won't transfer any movement in the bracket into the strut tube, so no.  The only real problem with it is the inefficient connection with the spar tube itself where the bolts are both removing meat from the critical tension and compression axis, and also promoting flattening of the tube when bending is applied, further weakening it.


text:
Can a weather balloon move horizontally?
How does a hobby weather balloon control its flight path? Just it just keep rising straight up vertically, always at the mercy of the winds, being swayed side to side?
Unlike a rocket/drone, it does not have an engine/motor that can be controlled remotely. So if I want the balloon to hover over a particular area and send me images (a particular section of a forest to watch for wildlife activity), how do I do it?
All weather balloons seem to be aimed towards gaining altitude and taking NASA like images, but is there a way to move a balloon horizontally and not just vertically

You can control a balloon horizontally but then we call it something else.

An ordinary weather balloon cannot maneuver horizontally (unless an external force is applied to it) because it lacks the means to do that. It has only one purpose, to soar up to the altitude where the air pressure inside is more than outside and then burst.
If you want it to steer, you can add steering servos (as mentioned in this PDF). Of course this will add cost and complexity.
There are some websites for Balloon Trajectory Forecast, which might be helpful.
Only if Larry Walters had thought about this, things would have been different for him.

Yes, I think a balloon can move horizontally the same way a cloud can (by wind).

if I want the balloon to hover over a particular area and send me images (a particular section of a forest to watch for wildlife activity), how do I do it?

I think I've got a simple answer to this one: Use a rope.
At least for a small balloon that's only 1 or 2 hundred feet up you could let it rise up like a kite and tie it off over your desired area. You might even be able to use a security camera wire to enable using a (relatively) cheap security camera, sending power & video up & down the wire, instead of a wireless camera. And you'll have the desirable ability to pull it back down to retrieve camera easily.
But, if you're thinking of using a giant weather balloon 1000+ feet in the air, I think that would create a hazard to aviation. [Does anyone know of any regulations or laws if that would be illegal anywhere? Canada/US/Europe?]

A weather balloon is almost constantly moving horizontally.  The only time it is not moving horizontally is when there is no wind and the balloon has no horizontal momentum (gained from rising through layers with horizontal winds).  You cannot control this horizontal motion and the balloon is at the mercy of the wind.
If you want a platform that is in control of its position, you will need something that can provide its own thrust.  A weather balloon is not going work for that application.  A weather balloon is also not designed to hover, but to rise until it bursts somewhere around 100,000 ft.

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text:
Are there commercial airplanes that are still flyable without any electricity?
I have seen the first episode of Revolution yesterday and there are all kinds of airplanes just falling from the sky because of complete loss of electricity.
I know most if not all modern planes use fly-by-wire systems.
I thought about this and the the question occurred:
Are there any still commercial airplanes in use that are still flyable with complete loss of all electric systems?
Do some commercial airplanes still have mechanical backup mechanisms to manoeuvre?

The question was about failing of all power sources or electrical systems at once. For example through an EMP.

Why did electric systems fail? Also, the best-selling jet airliner in history (the 737) is not FBW, so it's not even "most" airliners that are FBW --  among Airbus and Boeing, it's just A320 and beyond for Airbus and 777 and beyond for Boeing. @mins It's certainly possible, but anything that causes it likely leads to even bigger issues.

@mins, it is possible (albeit extremely unlikely), and I am pretty sure you need certification against that.

@cpast fuel starvation might easily be a scenario where you loose electrical but not hydraulic power

@Federico The RAT doesn't require fuel.

@cpast only between 140 and 320 Kts

My best advice to you is to believe nothing you see on TV, especially mini-series like this.  Let's just say that they have a poor record for accuracy, especially on anything to do with aviation.

@Simon Anything to do with technology at all, for that matter.

@Simon, the lack of knowledge and accuracy of technical information on tv is so bad I am beginning to not trust them for eavin information within their specialty: making video.

Buffalo Airways still operates at least one DC-3 in passenger service - the flight controls on that aircraft are entirely mechanical (cable and pulley) with the exception of the wing flaps, cowl flaps, and landing gear/brakes. Probably not the answer you were looking for though...

There's an implicit assumption in this question that a "commercial airplane" is big and complex.   I've been on a commercial flight in a Cessna 172 (one paying passenger, short flight).

Sorry because of the duplicate - I searched but the other question didn't pop up...

Probably even Wright Flyer III would not fly as before after "complete lost of electricity". Even simple engines contain spark plugs and related electricity circuits, jet engines require the whole computer (FADEC). So even with control surfaces working, you would be limited to gliding.

Are there any still commercial airplanes in use that are still steerable with complete loss of all electric systems? Do some commercial airplanes still have mechanical backup steering mechanisms?

Yes and Yes.
On most(*) Airbus aircrafts,

In case of a complete loss of electrical flight control signals, the aircraft can be temporarily controlled by mechanical mode.

This is called MECHANICAL BACKUP and is the lowest level of control law (after Normal, Alternate and Direct Laws)
The aircraft can be steered:

Pitch control is achieved through the horizontal stabilizer by using the manual trim wheel.
Lateral control is accomplished using the rudder pedals.

The pilots are notified with:

A red MAN PITCH TRIM ONLY warning appears on the PFD.

But:

Both controls require hydraulic power.

This means that if the aircraft looses BOTH electrical and hydraulic power, is no more controllable.
Usually there are pressurised hydraulic reservoirs that allow to have a minimum of hydraulic power even if there is total loss of electrical power, but if there is substantial damage to the aircraft that has severed the hydraulic lines, this is no more applicable.

(*): beyond the A320. Functionalities vary in the following manner: (emphasys mine)

Primary Flight controls:
Back-up Control Logical evolution of A320 / A340 / A340-600 family:
Full Fly-By-Wire, with a “Back-up” as an additional precaution to keep control of the aircraft during temporary loss of:

all Primary Flight Control computers
all Electrical power supply

A320 : full FBW controls, mechanical Back-up (Pitch Trim & Rudder)
A340/A330 : like A320, additional Yaw Damper to improve Dutch Roll
  damping even in Back-up mode (BYDU with hydraulic micro generator)
A340-600 : like A340 for pitch, Rudder becomes fully Electrical (BPS + BCM : Back-up Power Supply + Control Module)
A380 : like A340-600 for Yaw control + BPS+BCM also power:

Electrical Pitch Back-Up (elevators) linked to side-stick
Electrical Roll Back-Up (ailerons) linked to side-stick
Pitch Trim (Wheel is replaced by Switches)

For the A380, in particular:

Active Stability Control functions:
All levels of control laws (Normal, Alternate, “Direct” and even Back-up) include a Yaw and Pitch damping function

It's not even true that most airliners use fly-by-wire. Among Airbus and Boeing models, the A320 and beyond use FBW on the Airbus side (note that the A300 was produced until 2007), and the 777 and beyond use it on the Boeing side. This is probably a majority of major commercial aircraft, but it's by no means a vast majority.
Among these aircraft, virtually all of them have a backup to the electrical system. On most Airbuses, there is a mechanical backup (which directly triggers certain hydraulic control surfaces); only on the A380 is this absent. The Boeing 777 and up have FBW, but the 777 also has a mechanical backup.
In addition, the 737 (one of the most common aircraft worldwide) has pure mechanical reversion -- it's controllable even with total loss of hydraulics, let alone electricity.

Very interesting, I didn't know this. Thank you.

Mostly controllable even with total loss of hydraulics - the 737 has full mechanical control capability for the ailerons and elevator, but limited mechanical rudder control (although, IIRC, this is due to the large amounts of force necessary to overpower the large aerodynamic loads on the rudder, rather than any inherent limitation of the rudder controls).

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Can someone explain to me why these planes just don't turn about their center of gravity?
Look at this one:

The thrust force from the engine should generate some clockwise moment, right? Why won't it turn and just crash then? I guess the wings generate some sort of anti-clockwise moment? Can someone explain this?

Just a note, this is not an airplane (or seaplane as its tagged) its a Ground Effect Vehicle http://en.wikipedia.org/wiki/Ground_effect_vehicle in particular this is a A-90 Orlyonok. GEV's have similar but different aerodynamics than an airplane as they are made to work only in ground effect. Some however can climb to significant altitude and they can all work over land as well as water.

@Dave yes, being a WIG will change the magnitude of the effect, but the principle is the same

@Federico I know I just thought I would mention that its not a plane mainly because i love how ekranoplan sounds :)

Doesn't the question apply to any single-engined airplane?

@jamesqf it applies to any aircraft whose thrust axis does not go through the center of gravity, including multi-engine ones.

@Federico: Ah, I think I misunderstood the question.  I thought it was asking about rotation about the long axis of the fuselage (roll), rather than pitch.  I guess the pitch answer just seems so intuitively obvious.

I think the problem with the question is that it's thinking 'clockwise' as seen from viewing the photo, whereas we're all thinking from the POV of a pilot.  So the pitch would be up-down, while clockwise would be a roll.

The thrust force from the engine should generate some clockwise moment, right?

If we take your photo as a reference (and thus we intend "clockwise in the picture plane"), yes, it is. It is called pitch moment, because it would change the pitch of the aircraft (in your case, a A-90_Orlyonok), and in the case shown in your picture is negative, because it would make the aircraft pitch down.

Why wont it turn and just crash then? I guess the wings generate some sort of anti clock wise moment?

Because the wings and the horizontal stabilizer produce a total net pitch moment that counteracts the one generated by the engine.
They do so by having the center of lift in a different location w.r.t. the center of gravity.

The "normal" configuration for airliners would have an opposite pitch moment due to the engines, since in that case the engines are usually below the wings (and, being usually low wings, below the center of gravity). It is well illustrated in this image taken from the FAA:

With the A90_Orlyonok, when changing the thrust is there a mechanism or electric unit to change the amount of "counter pitch" produced by the horizontal stabilizer? And is there something like that for airliners as well?

@Maverick283:  The horizontal stabilizer is mounted to counteract the nominal pitch moment from the engines.  The elevators are adjustable and provide pitch control for all needs, including weather, desired attitude, and changes in engine torque.

Okay but does the elevator adjust automatically or does the pilot have to do it manually when the engine torque changes?

@Maverick283 depends if there is an autopilot and is a different question that I encourage you to eventually ask.

@Maverick283 In a normal airplane is is usually not automatic unless autopilot is engaged. In the Ekranoplan it is automatic but is normally added on to the pitch moment of the top mounted engine - that is, ekaronaplans need to apply down-elevator most of the time thus the engine position actually aids the elevator. The reason for this is to prevent the ekranoplan from taking off like an airplane. The reason for that is that once out of ground effect the amount of lift generated by the wings would be drastically reduced out of GE and cause the plane to stall

@Maverick283 ... originally ekranoplans were manually piloted but pilots reported maintaining constant altitude over the water to be very difficult. Thus computer controls were added. There is a non-ekranoplan ground effect vehicle design that appears to not need computer control (it is non-ekranoplan because it is not Russian and the creator of said vehicle did not call it an ekranoplan - it also predates ekranoplans): it is the Lippisch reverse delta - basically a forward swept delta wing. Google "airfish"

If you look closely there are two propellers on the tail, and they are contra-rotating, so one spins clockwise and the other counterclockwise so there is no roll moment produced.
See: http://en.wikipedia.org/wiki/A-90_Orlyonok

the question is about pitch moment, your answer is about roll moment.

@Federico: While you are correct about the probable intention of the questioner, the answer is valid for another way of interpretation.

No matter the exact design and careful balancing that goes into an aircraft, there is no general guarantee that all the moments cancel out. The direction and magnitude of pitch/roll/yaw moments vary with speed and altitude. Aircraft typically require active control surface inputs to stay level; these inputs can be re-centered or "trimmed" using trim tabs (which are usually located on the trailing edges of the control surfaces) so the pilot doesn't have to actively run the inputs.

Not to mention putting a bottle of duty free Scotch in the overhead bin will shift the C of G upward, and necessitate a change in control input...

There are also engines in the nose with their exhaust pointing below the leading edge of the wing.  Although, according to wikipedia, these engines can be turned off during cruise, when on, these engines would provide a pitching moment to counteract the nose-down pitching moment from the turboprop.


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What are the advantages of Chemical Oxygen Generation over Gaseous Canisters on board of aircrafts?
I'm looking to get a bit of info on Chemical Oxygen generation, especially as done on aircraft. I understand the process of Chemical Oxygen Generation. I'm also aware that weight for weight it produces far more oxygen than Oxygen gas canisters.
What I want to know is are there any other advantages? Does it have added safety benefits when compared to high pressure gaseous oxygen storage? The Oxygen candle burns extremely hot when it goes off but I'd imagine high pressure gas canisters could be far more dangerous and prone to exploding if damaged?

Are you trying to ask why oxygen generated in case of emergency in an airplane is chemical instead of using oxygen bottles? I do not see the link with aviation

I'm voting to close this question as off-topic because this question needs migration to engineering.SE...

Apologies if I've placed it in the wrong place, yes I was aiming for the emergency oxygen generation aboard aircraft in the case of depressurisation and why airlines prefer to use the chemical version rather than canisters

I'm no expert on this one, but airlines don't really need a reason besides "weight for weight it produces far more oxygen than Oxygen gas canisters." Nobody wants to waste money flying a heavier thing around the world when a lighter version is available.

Very legitimate aviation question. Commercial aircraft have both pressurized gaseous oxygen cylinders and chemical oxygen generators. We already have a pile of O2-related questions in the sidebar,

One advantage of generators is zero maintenance. They are simply life limited parts and require no maintenance until used or calendar expired.

Pressurized oxygen tanks have two big minus points: they are heavy, and they are essentially a small bomb. But they have two big plus points: they can be refilled easily and they don't generate any heat when you use them.
Chemical oxygen generator plus points are they are lightweight, self-contained and more-or-less maintenance-free (they don't leak). Minus points are they are single-use, time-limited and cannot be shut off.
As nearly everything in aviation is a balance of good and bad, we often see both systems being used at the same time. The flight crew will use oxygen on a regular basis - sometimes procedurally, sometimes just to clear up a headache. They need to be able to turn it on and off, and the airline doesn't want to replace the system each time.
Passengers rarely need oxygen, and when they do it's only until the plane descends to breathable altitudes (which will happen really quickly).

An oxygen bottle is extremely heavy. And when you are on fire you don't want to have oxygen around. And in general when you have to use oxygen in an aircraft, something went wrong. A big jet is about 40 meters long which means you have at least 40 meters of oxygen pipe. By requirement oxygen should be provided from maximum altitude to around FL100 which means 20 or 30 minutes. 435 passengers needing 30 minutes of oxygen means 1 ton of deadload. Replenishing an oxygen bottle is a pain for maintenance (tank temperature, pressure, ...). Maintenance and weight are key factors in the decision.

This seems to suggest that bottles have no benefits and aren't used. Also, your math on that 1 ton is not really clear.

When an aircraft is on fire you probably don't want to have the chemicals used in the oxygen generator around either.

The disadvantages of stored oxygen are that the cylinder can be very heavy, and it contains pure oxygen which can explode on contact with fire or a source of high temperature. However, it can last longer the flow is by demand when the person inhales. This means it can last longer than the chemical generator oxygen supply.
The chemical generator is cheap, doesn't need frequent maintenance and checks, and can supply oxygen for a larger number of people without adding weight to the aircraft because the oxygen is a byproduct of the burning of Sodium Chlorate. The cons are it is one time use and can only supply oxygen for about 15-20 minutes. This means the pilot will only have enough time to descend to a lower altitude. Another disadvantage that it is a continuous supply device, whereby it will continue to supply the oxygen even when you don't need it. Once it is activated it won't stop until all the Sodium Chlorate is used up to produce oxygen.

Oxygen doesn't explode by itself, even on contact with fire. It makes explosion possible when fuel (another gas or dust) is present. If you mean the cylinder which can explode when overheated, it can, but this (almost) doesn't depend on the gas inside.


text:
Can microbursts occur at high altitudes?
I was wondering whether a microburst can occur at high altitudes?

What does high altitude mean?

Strong downbursts of air are possible at high levels also, for example in Cumulonimbus-clouds. However I wouldn't characterize them as microbursts, since the change of airflow direction is an equally dangerous and defining factor in microbursts.

(source: weather.gov.hk)
The head/tailwind parts don't exist at higher altitudes and you would experience the downdraft merely as turbulence.


text:
What is the difference between slice, segment and leg?
I have heard of the terms slice, segment and leg. Since I am a newbie in travel industry, I would like to know and understand the basic differences between the three.
Could someone please explain the three, using some kind of example?

Looks more from food industry

@TrebiaProject.  or something from math.SE  ;)

Where did you hear "slice"?

Slice is a term invented by ITA Software. It refers to travel intent. E.g., "starting from Boston, I'd like to go to London, and then Tokyo" — the slices would be BOS-LON and LON-TYO. An itinerary servicing those slices could be composed of any number of segments.

I'm pretty sure those terms are not used consistently across all organisations in the air travel industry.
They are not defined in an IATA glossary I looked at but I did find this:

Definition of Flight Segment
The International Air Transport Association (IATA), the international trade body for airlines around the world, defines a flight segment as the operation of a flight with a single flight designator between the point where passengers first board an aircraft and the passengers' final destination. A flight designator includes an airline code, which has two letters or a number and a letter in combination, and a flight number of up to four digits. A flight segment can include any number of stops where passengers board and deplane the same aircraft operated by a single airline.
Comparison of Flights and Legs
A flight is defined by the IATA as the operation of one or more flight legs with the same flight designator. Unlike a flight segment, a flight may involve one or more aircraft. The IATA defines a leg as the operation of an aircraft from one scheduled departure station to its next scheduled arrival station. A flight segment can include one or more legs operated by a single aircraft with the same flight designator.

From eHow

Segment is used pretty consistently, simply because the major booking organisations (Sabre, Amadeus et al) use it in the same way. The "PNR, Passenger, Segment, Seat" relationship is universal, in my experience

This answer contradicts the quoted definitions from the IATA globssary below: There, a flight segment can theoretically involve an aircraft change at some airport as long as the flight number doesn't change. Can you please square this discrepancy?

@einpoklum A flight number may have two legs with diferent planes. For exampl, the segment BCN-MAD-SCL may be called IB-2312 where BCN-MAD is a leg and MAD-SCL is another. And both use diferent aircraft as the range is very different.

@borjab: So, a flight is made up of one or more segments, which are made up of one or more legs each. Segments end when the aircraft is changed (or at the last endpoint). But - can there be de-planing/disembarkation between the legs of a single a segment?

This is better than the accepted answer.  To put it more succinctly.  A leg is what the aircraft flies from takeoff to landing.  A seg is how the journey is marketed and sold.  So if a plane or planes flies from LHR to DUB to JFK thats 2 legs but 3 segs.  Legs : LHR-DUB and DUB-JFK.   Segments LHR-DUB, DUB-JFK, and LHR-JFK.

From IATA passenger glossary:
Leg:

The operation between a departure station and the next arrival
station.

Segment:

A leg or a group of legs from boarding point of a passenger to a
deplaning point on a given flight.

Sometimes referred to as "City Pair".  The operation between board
point and any subsequent off point within the same flight number.

Leg vs Segment in layman terms:

A leg stops when the plane lands.
A segment stops either when you change flight number or when you
arrive at one city where you want to spend time.

One segment includes one or more legs from the same flight number. Sometimes a plane lands to refuel or to load other passengers but is technically the same flight number. Every ticket's coupon represent a segment.
It is the first time I have heard the slice term.

The link is no longer working.

Updated. Thanks @PreetSangha

Update to the IATA page, the Airline Industry Data Model has a glossary in .xls format attached as a Resource
https://www.iata.org/en/programs/passenger/industry-data-model/

@Alx I have updated the link. But IATA has a tendency to change it without warning

appreciate the update, especially for those who end up looking for it as I did. Placing a glossary in an excel sheet also is not the most discoverable place..

As defined by others:

A leg is always a single non-stop flight.   Example, UA123 from BOS-EWR is a leg.
A segment is a flight operated by a single flight number, but may have an intermediate stop....Example - UA 234 from BOS-ORD-SFO is a segment

"Slice" is a newer and less used term in the travel industry:

A slice can be a single flight segment or multiple flight segments to get from origin to destination, possibly with a connection, but without a stopover.

Example- round trip itinerary with two slices
Slice 1 -   UA123/15NOV BOS-EWR
Slice 1 -   UA234/15NOV EWR-SFO
Slice 2 -   UA345/25NOV SFO-BOS

Welcome to [Aviation.SE]! If you will take the [tour], that will help you get a good feel for the place. It looks like you've got a nice answer, it would be a great answer if you could tell us who the "Others" are that provide these definitions. Possibly include a link to where we could do more searching would be great too!

I am directly quoting from the book 'A Dictionary of Travel and Tourism Terminology' by Allan Beaver.

"sector, segment or leg: A sector is, by definition, a portion of an itinerary, or journey, which may consist of one or more legs or segments. A leg is the portion of a journey between two consecutive scheduled stops on any particular flight. A segment is that portion of a journey, from a boarding point of a passenger, to a deplaning point of the given flight. Although the passenger may not leave the plane, it may tough down to take on or let off passengers at several points, so that a segment may be made up of a leg or group of legs."

Leg: The space between two consecutive scheduled stops on any given flight.
Segment: A leg or a group of legs from boarding point of a passenger to a deplaning point on a given flight.
Gap: That part of an itinerary (except the distance between two airports serving the same city) involving transportation by means other than by a scheduled service.
Itinerary: A single flight or a series of identical flights defined by a continuous Period and Days of Operation (and Frequency Rate if applicable), each of which consists of one or more contiguous legs which, taken together, describe the complete routing of that flight.
Itinerary: The sum of all portions from beginning to ending of passenger's trip (journey), even though separated by gap(s).
Portion: One segment or consecutive segments (even though gap intervenes) via any one Member.

Source: IATA glossary (.xlsx; iata.org)

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text:
Does the AC-130 have de-ice or anti-ice protection for wings and surfaces?
Does the AC-130 have de-ice or anti-ice protection for wings and surfaces? Can it fly in icing conditions? Looking at many pictures I see no sign of a shiny "hot wing" leading edge nor any boots. Does anyone have more information on this?

The C-130 uses pressurized bleed air for leading-edge and window anti-ice. The props are deiced with electric heaters in the prop.
Source
The C-130 is very often used in places that experience icing. For example, the US Air Force flies the C-130 as a cargo/transport aircraft for Antarctic and Greenland operations:

(Source: Popular Science)

Alright, I didn't figure that it had enough spare compressed air to use bleed air for that, being a turboprop and not a jet (usually much higher volume at higher compression). Is that just extremely high temperature paint on the leading edges? It's not polished like civilian aircraft that use bleed air for deicing.

I'm not sure of the temperature, it is probably somewhere around 250° where it starts out. All 4 engines are capable of supplying bleed air I believe.

Bleed air in the Herk is both really hot & also quite plentiful. All 4 motors turn at 100% RPM the whole time, and compressor stage where it is bled from (used to know that offhand, but haven't flown the Herk in quite a while) was hot as well, 600 degrees comes to mind. In jets, power to idle reduces your bleed pressure quite a bit; in the Herk, it doesn't matter.  (My experience was on E and H model Herks, the J model has different motors & may not be the same.)

As someone who had a very brief stint working on the AC-130 in Iraq (helped with some tricky troubleshooting problems), with the rest of my experience being on "regular" C-130's, the gunships often had creative alternative systems to their "regular" counterparts. While it's been too long since I've worked on them, and I can't remember specifics, I wouldn't outright assume that what is normal on a C-130 is normal on an AC-130. It most likely is the same setup, but even if I could remember specifics, they try to keep details classified.

@Frank -- it'd be weird if the de-ice got ripped out/changed drastically though (as that's a rather basic system for just getting the plane from point A to point B in many parts of this world).

"being a turboprop and not a jet". It's a jet. In fact some small %age of total thrust is coming out the exhaust. Bleed air temp is about 600F. The great debate has always been "turn it on and leave it on", or "turn on only as needed." Left on, the temp regulates and the flow does reduce. It is not unusual to turn off all bleed air during takeoff if runway length, obstacles, gross weight, air temp/pressure warrent. Fun fact: (Some) C-130's taking off for the Grenada invasion were beyond even the "emergency war weight". You know they had it off.

@UnrecognizedFallingObject No doubt, I'm pretty sure you're correct. I just wanted to throw caution to the wind that the AC-130 is a different animal than the C-130E/H model, and that it's best not to assume that because the "normal" C-130 had something or did something a certain way, that the AC-130 should be presumed to be the same. Not trying to stir the pot, just throwing it out there.

@radarbob -- yeah, bleeds off would make sense for a max perf T/O procedure on any large turbine A/C.


text:
Extent of ATC control on an aircraft
Are there any systems in a manned aircraft which can be controlled by the ATC/ground control.
To be specific, could you name some tested and existing procedures/systems which make it possible to change aircraft dynamics such that it is manipulated from outside the cockpit of the aircraft and the pilot is overridden?

@fooot: Thanks! :)
But that question only debates the risks of such a system. I ask whether any existing flight system has been tested for this capability.

The risks are all the reasons why it hasn't been built or tested for manned aircraft.

@fooot: So it hasn't been done, and does not pose a security risk on current aircraft?

A system that allows external control to override will be fairly unpopular with pilots.

There is one system with is controlled by the ground, but the pilot can shut it down. A current popular trend is to prevent this pilot action in the future, because many people think the pilot is not reliable. This system is the SSR transponder which replies to SSR interrogations.

@mins: I wanted an answer like this. Could you substantiate? Any text/document?

It is not a positive answer to your question "possible to change aircraft dynamics", rather it shows ATC actions are actually very limited to interrogations and can't interfere with piloting AFAIK. I can expand and document in this direction if you want. But the question needs first to be reopened.

Nothing on board a manned aircraft can be controlled from outside. The only people that control it will be both pilots in the cockpit. ATC now has only the capability in knowing your ssr mode c or mode s that gives them information about your current altitude and speed

authors: Hữu Đạt Đoàn


text:
What variant of Mi-8/Mi-17 is this near Kennedy Space Center?
A tweet by Julia Bergeron showing pad activity near Kennedy Space Center also showed what seems like an unusual visitor for the area.  I've attached the relevant picture.  It's clearly in the same family as the Mi-8, but has the following unusual features:

The tail rotor is on the left, which I think places it in the Mi-17 (export) family?
The rear doors are a flat ramp, not a clamshell
There's a lump over the right door that might be a winch but also distinctly reminds me of the heater bulge forward of the right main landing gear on the Mi-8s that I'm used to, which this seems to lack?
It's a five-blade main rotor and three-blade tail rotor, so I don't think it's one of the newer Mi-38s.

The closest I've come so far is an Mi-17MD, but I'm not fully satisfied with that identification.

Interesting. It must be "a" Mi-17, but I've never seen this version. Perhaps indeed MD.

I edited the title as what you were asking was not explicit. Feel free to edit it again if this is not what you want to ask.

@ManuH I want to know what variant it is.  As I lay out in the question, it's got to be an Mi-8 or Mi-17 variant, I just don't know what one.  So I guess I'll edit it again.

It may be N25308 owned by Vertol Systems Co out of Destin Florida. They have a 1986 MIL MI-17 HIP-H.

Hmm.  Hard to say for sure, because Just Helicopters says they do Mi-8 modernization and so it could be one associated with them rather than one they own.  The Destin Log shows photos from a few years ago of a clamshell-rear Mi-8 associated with Vertol...Google maps shows 3 Mi-8s sitting at Destin airport though, so huh.  Not exactly close to KSC, but Mi-8s have long legs.

Of minor interest:  this Warzone story calls a helicopter with similar but not identical features (there's a sensor turret on this one under the right nose) an Mi-171E, though Wikipedia says that's a variant with engine upgrades for extreme temperatures.

I have a better candidate than the Mi-17MD now:  what I think is the next version after that, the Mi-17V-5.  The feature that really prompted the question was the heater not being in the place I'm used to; the V5s have an enlarged right-side door, and that apparently necessitates moving the heater to the top-right position (from where the KO-50 used to be, right, extending from the same bulge that extends forward from the right main gear).  Oddly, it's not clear to me if all V-5s share the door or not--Airforce Technology makes the right-side door sound optional, and it's tough to tell if various internet sources are just using stock of any Mi-8 when they refer to some country or other purchasing V5s or if they're making sure they're getting it right.  Mi-17MDs in the service of the Colombian Air Force seem to delete the heater unit altogether.
The only other thing I'm wondering about now is the large open hatch above the right-side landing gear.  Most Hips have round windows there.  That might some kind of optional equipment though.
...there also may be a roundel just behind that hatch, but I can't tell what it is.  The CH-178s had similar roundels there, but I really really don't think it's one of those.


text:
Were there any instances of aerial combat between helicopters?
Were there any cases in history where two attack-helicopters like AH-64 and MI-24(for example) were involved in an air fight between each other?

Here's a recording of helicopters "dogfighting":
https://www.youtube.com/watch?v=lyuULnLsc4w

@USER_8675309 That is not a "recording", it is a scene from a movie, 100% dramatization and not a representation of real combat.

@RonBeyer it is most certainly a recording

@USER_8675309 Yeah, you're right, I forgot that Nicolas Cage used to be an Apache pilot and that Fire Birds is a war documentary.

@RonBeyer Glad we can agree

@RonBeyer: How do you think movie producers get the scene onto the cinema screen? Magic?

Yes, there has:
In the Iran-Iraq War, Wikipedia:

The war also saw the only confirmed air-to-air helicopter battles in the history of warfare, with Iraqi Mi-25s flying against Iranian AH-1J SeaCobras on numerous occasions. The first instance of these helicopter "dogfights" occurred on the first day of the war (22 September 1980): two Iranian SeaCobras crept up on two Mi-25s and hit them with TOW wire-guided anti-tank missiles. One Mi-25 went down immediately, the other was badly damaged and crashed before reaching base. The Iranians won a similar air battle on 24 April 1981, destroying two Mi-25s without incurring losses themselves. According to unclassified documents, Iranian pilots achieved a 10-to-1 kill ratio over the Iraqi helicopter pilots during these engagements and even engaged Iraqi fixed-wing aircraft.

These would be pretty loosely classified as a "dogfight" since the Iranian AH-1J's "crept up" on the Mi-25's. It is doubtful that the Mi's did any kind of evasive maneuvering or that the AH's did any kind of aggressive pursuits, but it is air-to-air combat between helicopters.
The page from the Mi-24 page gives a little more detailed report:

This war also saw the only confirmed air-to-air helicopter battles in history with the Iraqi Mi-25s flying against Iranian AH-1J SeaCobras (supplied by the United States before the Iranian Revolution) on several separate occasions. In November 1980, not long after Iraq's initial invasion of Iran, two Iranian SeaCobras engaged two Mi-25s with TOW wire-guided antitank missiles. One Mi-25 went down immediately, the other was badly damaged and crashed before reaching base. The Iranians repeated this accomplishment on 24 April 1981, destroying two Mi-25s without incurring losses to themselves. One Mi-25 was also downed by an IRIAF F-14A.
The Iraqis hit back, claiming the destruction of a SeaCobra on 14 September 1983 (with YaKB machine gun), then three SeaCobras on 5 February 1984 and three more on 25 February 1984 (two with Falanga missiles, one with S-5 rockets). After a lull in helicopter losses, each side lost a gunship on 13 February 1986. Later, a Mi-25 claimed a SeaCobra shot down with YaKB gun on 16 February, and a SeaCobra claimed a Mi-25 shot down with rockets on 18 February. The last engagement between the two types was on 22 May 1986, when Mi-25s shot down a SeaCobra. The final claim tally was 10 SeaCobras and 6 Mi-25s destroyed. The relatively small numbers and the inevitable disputes over actual kill numbers makes it unclear if one gunship had a real technical superiority over the other. Iraqi Mi-25s also claimed 43 kills against other Iranian helicopters, such as Agusta-Bell UH-1 Hueys.

I don't believe there has been any recorded instance since the Iran-Iraq war, but during that conflict there were multiple instances of helicopter-vs-helicopter battles.

Was going to add my own answer, but since you've covered the one major instance of a helicopter dogfight, I won't. You may want to add, however, the scarcity of such fights is mostly because attack helicopters are designed for attacking ground-based targets. Essentially, they're not designed for aerial dogfighting.

@Omegacron Actually according to the J-CATCH study the US Army conducted, Helicopters are extremely effective at aerial dogfighting especially against fixed-wing targets. So much so that fixed wing pilots are told not to engage helicopters unless from a distance or high altitude.

Interesting, didn't know that. That might explain some of the drastic design changes we saw in models like the Apache and Comanche, which were built after that.

@RonBeyer -- I wonder what tactics made helicopters so effective against fixed-wing targets?

I don't know a whole lot about these things, but from what i know, taking out a helicopter with a TOW rocket launched from another helicopter sounds like a laudable achievement.

These would be pretty loosely classified as a "dogfight"  Von Richtoffen would have recognized it as such, given that he taught how important it was to see the other guy first, to shoot first, and to shoot straight.

Wasn't aware of that battle during the Iran-Iraq war but gunships can and do carry air-to-air weapons.  The Apache can carry an air-to-air version of the FIM-92 stinger missile and the USMC's new AH-1Z Viper can carry the same as well as the AIM-9 Sidewinder series of missiles.

The 20mm rotary cannon comes in pretty handy for close in bandits as well.
Hollywood fantasies like Airwolf, Blue Thunder, and Firebirds aside, helos really aren't that great at ACM.  Airframe and rotor load limits usually restrict operation to around +2/-1Gs and the ship's are limited in the kind of maneuvers possible.  A2A weapons on helos are at best a last ditch defensive weapon and the helo - even gunships - were never intended to seek and destroy other aircraft.

J-CATCH Phase III: "... the outcome was a 5-to-1 ratio in favour of the helicopters."

As Judge Dredd would say "......interesting."

You can't tell me Airwolf is fantasy :-(


text:
What is a "Major Airline"?
Which airlines can be designated as "major"? what difference between them and other airlines?
What qualities airline should have to be "major"?
I can't find any proper description, but I heard about it a lot from aviation news.

Perhaps we should start by defining what an airline is, much less a major one.

Unofficial Terminology
In the United States, the unofficial term Major Airline is likely based on various official FAA and DOT terms. I cannot speak to use of the term outside the United States, but it may be similar, if used at all. This answer will address use in the context of US law and FAA regulations.
If a definition of Major Airline is to be faithful to official sources, that definition could be one such as the following from BusinessDictionary.com:

US designation for an air carrier with annual operating revenue of more than one billion dollars, such as American, Northwest, and United Airlines. Also called major carrier.

However, as voretaq7 pointed out, the term Major Airline can be used to refer to the traditional "Legacy Carriers"—as opposed to newer start up carriers, the "Regionals", or low cost carriers. The terms are sometimes used interchangeably.

Official Terminology
The official terminology from which Major Airline is likely derived has a regulatory basis in 14 CFR 241, Section 4, "Air Carrier Groupings". This section describes the basis for grouping of Large Certificated Air Carriers, and defines the various groups. The following gives the criteria for assessing the level of operations (note that the nature of operations is assessed separately):

(a) All large certificated air carriers1 are placed into three basic air carrier groupings based upon their level of operations and the nature of these operations. In order to determine the level of operations, total operating revenues for a twelve-month period are used. The following operating revenue ranges are used to establish air carrier groupings:
 Carrier Group      Total Annual Operating Revenues
 I                  0-$100,000,000
 II                 $100,000,001-$1,000,000,000
 III             $1,000,000,001 +

The DOT's Bureau of Transportation Statistics provides the following similar, but simplified, definition of Major Carrier Group:

Major Carrier Group: Air carrier groups with annual operating revenues exceeding $1,000,000,000.

Answer
Thus, to answer your question as to what is required for a US "airline" to be designated as "Major" in an official capacity, the "airline" must:

Be a Large Certificated Air Carrier (see definition below), and
Have a reported annual revenue of more than $1,000,000,000.

Definitions
The following are definitions as given in 14 CFR 241, Section 3, "Definitions":
1Large Certificated Air Carrier:

An air carrier2 holding a certificate issued under 49 U.S.C. 41102, as amended, that: (1) Operates aircraft designed to have a maximum passenger capacity of more than 60 seats or a maximum payload capacity of more than 18,000 pounds; or (2) conducts operations where one or both terminals of a flight stage are outside the 50 states of the United States, the District of Columbia, the Commonwealth of Puerto Rico and the U.S. Virgin Islands.

2Air Carrier:

Any citizen of the United States who undertakes, whether directly or indirectly or by a lease or any other arrangement, to engage in air transportation3.

3 Air transportation:

The carriage by aircraft of persons, property, or mail.

In the US "Major Airline" is a DoT designation that refers to airlines (Part 121 carriers) with over $1Billion in annual revenue.
It is distinct from "legacy carriers" - the ones that existed prior to airline deregulation in 1978 - though the legacy carriers tend to be major airlines (American, United, Delta, Hawaii Airlines, and Alaska Airlines are all "Major Airlines") and the terms are often used interchangeably.

Is this term used in the world, not only in US?

@wiaim I'm sure other countries use the term - or its equivalent - but I can't speak to what their official definition of the term is (or if they even have one - it may be used as an informal term in other countries with a meaning akin to "Airline whose name everyone recognizes from TV ads").

I don't think I agree with this answer as worded. The DOT seems to use the term "Majors" or "Major Group" to refer to Group III air carriers designated under 14 CFR 241 Section 4. As far as I can tell the colloquialism "Major Airline" is based on these designations, but has no official status.


text:
What alternative designs competed for the C-130 in the 1950s?
Which manufacturers and aircraft entered the U.S. government design competition back in the 1950s in which the Lockheed C-130 was selected? Were they all clean sheet designs, modified versions of current aircraft, or unmodified aircraft already in service? Is there any documented history which states justifications for the Lockheed design?

By "justification" do you mean "why Lockheed won" or something else?

So whenever the DoD selects the winner of an aircraft design competition, they provide a document which outlines the justifications for the decision. The F-35 decision, for example provided that while the Boeing article demonstrated the capabilities of vertical take-off /landing as well as Super Cruise operations, the aircraft could not do both without first being reconfigured. There were a few other key justifications with that were cited as well, not to mention that the Boeing version looked absolutely ugly, like UGLY ugly. If you're gonna be ugly, you better be an A-10! Beautiful ugly!

The competing companies (ones that elected to compete anyway, more were invited) were Lockheed with two submitted designs, Boeing with one design, Chase Aircraft with three designs, Douglas with three designs and Airlifts Inc with one design. As far as I can tell, these were just designs and Lockheed won the contest based entirely on paper. The YC-130 was ordered and after performance was verified, it went into production in 1954.
It doesn't look like there is any public information on the competing designs since they didn't leave the drawing board. It is unlikely that any of them are "clean sheet" designs. The Boeing submission was probably (and this is a personal guess) based on the C-97 Stratofreighter. The C-130 itself looks to be an up-scaled version of the Fairchild C-123 Provider with design elements from the Chase XCG-20 (which was developed into the C-123).
I'm not sure what you mean by "justifications for the Lockheed design". Given that it is the United States military's most successful aircraft design ever, with 60 years of continuous service, I'm sure every design was driven by a contract or performance requirement. Here is a good article about the C-130 designer, Willis Hawkins that gives some insight into the project.
Most of this information was taken from the Wikipedia page on the Lockheed C-130 Hercules.

So yeah, "justifications" was meant exactly as you said, however not meant to imply malice. I absolutely love the C-130 design and celebrate the fact that it's design was so wrk thought out that it's effectiveness has persisted for so long, and will continue to for decades. I really enjoy learning about the histories surrounding USG, and especially DoD aircraft design competitions and decisions. I absolutely love that we have a number of airframes that were so well designed that they are still being used effectively in the US military, albeit with appropriate modernization upgrades, simply

Because one cannot design an aircraft that would be better. I submit as additional examples the A-10, B-52, UH-60, AH-6, etc. I find it especially interesting when you contrast those historic processes with more recent examples, such as with the F-35 and the LRB planned B-2 replacement. Today the UH-60 is 3 years from its 40th birthday. When you consider that when it was introduced as a replacement of the UH-1 Iroquois (Huey), the Huey was only a20 year old design. The Blackhawk is still being produced new with existing aircraft being upgraded, modernized, and modified and another 30 years!

I tried to search for the General Operating Requirement for the C-130 (basically the design spec) but couldn't find one. Allegedly it was only a 30 page document but very well written in that once the Lockheed design was chosen very few changes had to be done, mostly with layout of controls.


text:
Which civil airport has the longest runways in total?
It's quite easy to google information about which civil airport has the longest runways, but what I'm really looking for (and having a hard time to find) is which airport has the longest runways in total - I mean if you add up all the lengths, disregarding the direction - which one be the winner?

Makes sense, let me edit the question to make is specifically about civil airport.

I'm pretty sure all of Rogers Lake is at least somewhat suitable for use as a runway :P

Perhaps the Black Rock City Munincipal airport (88NV: http://www.airnav.com/airport/88nv ).  Though it's officially only 7000 ft, it has upwards of 40 miles of unpaved landing area available if needed.  And room for quite a number of parallel runways, too :-)

To add to Unrecognized's comment, if you add up all the paved and dry lake bed runways at EDW, well that's 213,244 feet.

Related: Which civilian airport has the most runways (current and planned)?

Best I can find, within the US, is KDFW with 80,403' of total length. Second seems to be KDEN with 76,000'. Glanced at KORD, and with mental math it comes up to about 71,000'. Most other major airports are well behind all of these, mainly because they don't have as many long runways as DFW and DEN.
Somebody else can consider Russian, Chinese, and Middle Eastern airports -- I don't have the chart sets handy for those.  May be worth converting this to a community wiki answer if any of those places give interesting results.

I thought of EHAM, but it's only got 63,800.

Based on my current navigation database (AIRAC 1911), the following 20 airports have the longest total runway length:

KDFW: 7 runways with a total length of 80,403 ft (longest 13,401 ft)
KDEN: 6 runways with a total length of 76,000 ft (longest 16,000 ft)
EHAM: 6 runways with a total length of 63,688 ft (longest 12,467 ft)
KORD: 7 runways with a total length of 62,342 ft (longest 13,000 ft)
KDTW: 6 runways with a total length of 57,713 ft (longest 12,003 ft)
KEDW: 4 runways with a total length of 56,143 ft (longest 21,119 ft) (not civilian)
LTFM: 4 runways with a total length of 51,508 ft (longest 13,451 ft)
KIAH: 5 runways with a total length of 50,403 ft (longest 12,001 ft)
CYYZ: 5 runways with a total length of 49,955 ft (longest 11,120 ft)
LEMD: 4 runways with a total length of 49,761 ft (longest 13,711 ft)
KATL: 5 runways with a total length of 49,389 ft (longest 12,390 ft)
ZSPD: 4 runways with a total length of 49,212 ft (longest 13,123 ft)
ZBAD: 4 runways with a total length of 48,556 ft (longest 12,467 ft)
LIRF: 4 runways with a total length of 48,272 ft (longest 12,802 ft)
PHNL: 6 runways with a total length of 48,264 ft (longest 12,312 ft)
LFPG: 4 runways with a total length of 45,085 ft (longest 13,780 ft)
KJFK: 4 runways with a total length of 44,990 ft (longest 14,511 ft)
KLAX: 4 runways with a total length of 43,829 ft (longest 12,923 ft)
KLAS: 4 runways with a total length of 43,800 ft (longest 14,515 ft)
KMCO: 4 runways with a total length of 43,010 ft (longest 12,005 ft)

As Ralph J said in his answer, Dallas/Fort Worth (KDFW) comes first (also worldwide) due to the large number of runways (also highest worldwide, together with KORD). In Europe, the winner is Amsterdam Schiphol (EHAM) and in Asia, the winner is Shanghai Pudong (ZSPD).
In total 11 out of the 19 civilian airports listed above are in the United States.
The highest average runway length of the 19 civilian airports listed above has Istanbul Airport (LTFM) at 12,877 ft.

Qamdo Bamda Airport (ZUBD) has one runway that measures 18,045ft.(5,500M) long

The question is asking for the highest total runway length, i.e. if you add all runways together


text:
What advice would you give a novice pilot on controlling the rudder?
I've recently picked up flying lessons for ULL (similar to LSA in N.America). I've thought I've been doing pretty well (I guess my experience with computer simulation helped considerably).
Yet more and more I seem to have trouble with my feet and controlling the rudder - my instructor(s) tell me that I just seem to be "unwilling" to move them, yet it just seems to me somehow unnatural and awkward.
Are there some tips for novice pilots on how to dive into the rudder-control, best feet stance etc? (I tried to do a web search but couldn't find anything useful.) Or is it a normal thing for beginners to struggle with this?

Learn to fly a tailwheel aircraft: rudder use is absolutely essential there and you can't ignore it. Tailwheel pilots are moving their feet constantly. Or, one instructor suggested to me that I should fly around using only the rudder (instead of ailerons) for turning the aircraft. It's not the normal way to fly, of course, but the point is to force yourself to use the rudder, not to make perfect turns.

@Pondlife Changing the aircraft for the lessons is not an option (and I'm yet far away from learning yet another aircraft, even though I'm looking forward to that!). The rudder-flying seems like an interesting lesson. Is there any risk of too-much rudder while flying at safe speed?

@Czechnology Whether any such risk exists will depend on aircraft type. In the normal light GA planes used for flight training, there's not really much risk of that as long as you don't abuse it (i.e. don't wave it back and forth quickly while flying around, for example.) I'm not sure about ULLs, but I'd guess they're similar. Don't abuse rudder authority in an A300, though.

Check with your flying instructor, but in light Cessnas (for example) there's no real risk. If you hold the rudder in long enough on any aircraft then it will start to roll (there's a detailed explanation here) but in a typical trainer that will happen very slowly.

It's very normal for most students to struggle with the rudder initially.
One aspect that got me while learning to fly:
Unlike stick inputs is not 'applied pressure' that measures the effect of the rudder, but the actual physical displacement of the pedal. It was quite usual for me to feel the need for right rudder, increase pressure on the pedal but with very little actual pedal movement, so there was practically no effect on the a/c.
So I made a conscious effort when right rudder was needed to apply pressure enough To Move The Pedal.
In other words if you want to double the effect of the rudder you need to double the pedal displacement, not double the pressure applied.
Second thing that got me to using the rudder correctly:
Make a mental note to use rudder

when using the ailerons
when changing power settings.

Pretty soon these actions will become linked by the brain and you will do it unconsciously. Then with time you will also learn to use the correct amount.
On feet stance
I am pretty short at 1.70m so I was usually selecting the closest setting for rudder which was placing the rudders very close to my knees, and as such it was difficult to properly use them (as my body was literally resting on the pedals). I was once advised to push them further back and it has made a world of difference: adjust them so that maximum deflection requires just a little bit of hip effort and almost a straight knee. Try a couple of positions and see which one works best; your instructor can help to show you the proper adjustment, and it does make a word of difference.

Thanks for your tips! In normal turns, I'm already quite used to adjust the rudder accordingly (just as most students, my instructor's "ball, watch the ball!" will ring in my years for years to come) even though I'm yet far away from doing it subconsciously without watching the ball. But I struggle with it most during the takeoff and landing phases when the legwork probably has it's highest importance. After forty landings, only a fraction have been on my own.

I'm the same height as you. As for the position adjustments, my small aircraft doesn't offer any. So I'm "adjusting" with a pillow behind my back which seems to help. Not sure if enough or not. But I mostly asked about the best position of the feet on the pedals - I'm trying to use just the front of my feet, with heels on the ground. But during sharper inputs this tends to get awkward.

Feet position on the pedals is only important on the ground, if the brakes are controlled from the rudder pedals aswell. In that case heels on the ground is a must. In the air it doesn't make much difference, just keep your feet on the pedals and make sure none of your weight is being supported by the legs/pedals.

Ok, good to know. My trainer plane has the brake lever on the control stick so there's nothing but the rudder under my feet.

Fly a tail wheel airplane from the back seat, even if you don't learn how to land and take off. When you are sitting behind, instead of over the CG, you will feel every uncoordinated turn, and you will learn to use the rudder very quickly

You beat me to it!  My (very serious) answer to this is to go fly a glider to witness the importance of the rudder or buy some time in a tail-wheel and just practice landings for a few hours.  Either will demonstrate the role the rudder plays quite nicely.

The key is to fly from the back seat

At this point in the OP's training any exp will be very beneficial.

As I've said before, I am looking forward to learn to fly a tail-wheel plane but currently I am practicing only on one type. I've managed to get my license a few months back but there is still a lot of practice I need, especially on cross-wind landings.

Before you start up the airplane, make sure you can move all flight controls to their stops - full pedal, full aft column/stick. It may be a challenge for people of shorter stature. You may have to do a bit of fiddling around to find the right seat adjustments to accomplish this. Don't be shy to ask your instructor for help.
If you acquired experience on a desktop simulator without rudder pedals, it would be no surprise that their use will be unfamiliar.
One way to get used to working the rudder may be to practice sideslip. It's an important technique for an emergency (unpowered) landing because it's a good way to correct a too high/too fast approach (within limits) when you only have the one chance to get to your touchdown point.
It should be a natural thing when performing co-ordinated turns that as you bank the wing, you step on the appropriate (low side) pedal to correct for the leaning sensation and keep "down" feeling like it's straight through the center of your seat (as when the ball will be centered).

Full pedal on the ground is not really possible in aircraft where the rudder controls are connected to the front (or tail) wheel. I think sideslip helped me in some ways, because otherwise one never(?) uses a full deflection of the rudder, so it breaks some mental barriers. In the end, what really helps most is just practice and more practice. I've managed to get my licence a few months back :)

@Czechnology true. You'd probably only be able to feel for the stops when taxiing.

This can at times be difficult coordinate with other control inputs.  It's also going to vary from aircraft to aircraft, but there are some basic situations where using rudder inputs will always be required.
1) Intitating/ terminating a turn.  You'll always need rudder here to counteract adverse yaw from the ailerons.  Try this:  Execute several turns alternating from left to right and roll out straight and level once the turn is established and constant.  Apply rudder in the direction of the turn as you do so, then cross reference whether the ball remains centered.  If the ball is not centered, correct with rudder so that it is.  Make a mental note of how much rudder was needed to center the ball and then attempt to apply that much rudder on the next turn and repeat this process.  With a little practice you can begin to intuitively add the correct amount of rudder to correct for adverse yaw in a turn.  The same process will apply as you roll out of a turn.  Apply a rudder input coinciding with aileron input to roll out of the turn.  Cross reference this with the ball, correct so the ball is centered and so on.  Note:  the amount of rudder required to do so will vary with airspeed and bank angle.  But some solid practice will develop good motor memory for the inputs required over this range.
Cross control:  Outside of aerobatics, this is most often used for slipping an airplane to slow it down or for runway centerline alignment of the aircraft during a crosswind landing.  These maneuvers are going to be more difficult that making coordinated turns were as it is not terribly intuitive to cross control and aircraft and it will be done purely by feel and visual reference.  Skilled slipping of an airplane, I've felt requires the pilot to first visualize a line that he wishes the airplane to track all the way out to infinity, then intimate the cross control.  If the airplane begins to drift in the direction of the rudder input, ease off on the rudder and apply more aileron input until the aircraft returns to the intended track line.  If the aircraft drifts away from the track line in the direction of the aileron input, ease off the aileron input and apply more rudder until the airplane returns to the track line.  When using cross control in the roundout or approach in a crosswind landing, once you execute the cross control with aileron input opposite the direction of the crosswind component, you will use rudder to keep the longitudinal axis of the airplane parallel to the runway centerline.  Aileron input will be used to control the lateral translation from the runway centerline.  In other words, you will use rudder to keep the fuselage of the airplane parallel to the runway centerline and aileron to hold the airplane tracking along the runway centerline.

I guess its normal for beginners and more practice will help. It did for me anyway.
When I learnt, my instructor told me when I was turning to think Bank Angle-Back Pressure-Ball, and repeat this while the aircraft was turning so I could monitor the ball (glancing in and checking once every ten seconds, looking out the rest of the time).
If you are climbing or descending you will need rudder one way or the other.
The other main use is when you are turning, e.g. if you move the ailerons, you should move the rudder at the same time, but when you are at the correct bank angle, you come off the ailerons and also come off the rudder as a rule, just making very minor adjustments as part of the Bank Angle-Back Pressure-Ball routine.
So to start with, try to practice moving the rudder every time you move the ailerons, even if only making a minor correction to heading.
Finally, just as I was told I shouldn't be flying more than 30 degrees angle of bank at low level in the circuit, neither should you be using the rudder on its own, or cross controlling (right aileron, left rudder for example). Giving the rudder a big kick on its own at low speed is the recommended way to get into a spin, not something you want to do at low level. So while you shouldn't be scared of it, do respect the rudder and try to fly in balance at all times, particularly when at low level / low speeds.
I would like to add I'm not a flying instructor, I'm only trying to give you some helpful hints here. Hope this helps.

P.S. Also programming yourself to release back pressure and step on the sky (with the rudder) when you are near the stall is good practice and should prevent a stall/spin from occurring. Your instructor will be able to advise more on this one.

Isn't cross-controlling the technique used to counter side wind on takeoff/landing? As I've told Radu above, I have biggest struggle exactly during those phases. In normal flight, I've already learnt to check the ball in each turn and adjust the ball regularly.

Yes of course the wing down technique uses a small amount of intentional cross controlling. I guess I was talking about unintentional cross controlling. If you are going to cross control you need a good reason for it as it's dangerous if you do it by mistake without really understanding what you are doing.

Would just like to add, crosswind landings didn't click for me until I had over 100 hours... Just need to practice, practice..

authors: Δημήτρης Τσαρούχης


text:
Is there similar result between simulation and reality?
While designing an aircraft and analyzing it using simulation software, one result comes out. Is what occurs on the aircraft in reality similar to the result as given in a simulation?

It would not a "simulator" if the results were not similar.

See an example comparing simulation of flight dynamics and wind tunnel for the conversion of an Avro RJ85 aircraft into a fire fighting aircraft: Efficient high fidelity simulation of a special role aircraft in
transonic and high lift flight regimes using ANSYS Fluent and
ICEM Block Structured Meshing.

Theory behind CFD software: Computational fluid dynamics.

In short: The result depends on the input. Garbage in - garbage out is very valid in simulations.

Yes, usually
Simulators are pretty accurate, at least for the specific things they're programmed to measure and account for.
For example we have a pretty good idea how airflow works, so airfoil/wind tunnel simulation is very accurate. We also have quite good ideas of how materials react, flex, break etc, and can model them pretty accurately.
However
No simulation is 100% accurate: there is always potential for things in the "real world" to happen in a way we either didn't account for, or weren't expecting.
For example sometimes manufacturing flaws mean a material breaks in a way we weren't expecting, or an external influence changes the way something happens. We also don't have a 100% understanding of aerodynamics under all conditions.  This is why we still need real-world testing. There are also circumstances we've never encountered and therefore can't be certain of: eg aircraft are designed to handle around 150% of the force of the strongest known/experienced turbulence, but we can't be truly sure that this hypothetical 150% turbulence would act as "regular" turbulence, merely 50% stronger
In short: yes, the results will be similar, but they will not necessarily be identical, depending on exactly what you are testing.


text:
Do emergency services helicopters fly VFR when leaving base?
I've recently been watching an interesting documentary on helicopter paramedic teams. As you all probably know, their job consists of a lot of sitting around doing nothing before a scramble and then a short (or not-so-short) flight out to the middle of nowhere and back again. On the (UK) documentaries I've seen, the aircraft are usually based at reasonably large commercial airports, physically located close to the fixed-wing runways.
In order to find the guy lying injured in the field and help him out of asystole, they have to rapidly launch from a presumably busy airspace, and get there ten minutes ago. Do airports have procedures that allow them to always assume an "exit route" is always okay, under some ceiling? Do they have to get take off clearance as other private aircraft would? I understand that they get given priority ATC clearance when in controlled airspace, but quite often their target call-to-takeoff times are less than two minutes, and it seems unlikely that the nearby 777 on FA would be done that quickly.
What happens if it's not possible to be VFR entirely on route? I have seen cases reported where difficulties are encountered due to fading light halfway through treating a patient --
meaning that the pilot is worried he can't take off again. It seems rather odd that, if a pilot was able to land in a field comfortably with good visibility, he can't ask for a route to be cleared, file a flight plan, and go to hospital IFR.
For that matter, how do police helicopters chase the bad guys at night in zero visibility?
Disclaimer: I've never set foot in a helicopter in my life, but have a single-digit number of hours in light aircraft -- sick people are more my forte.

I don't know much, but I can tell you that some police helicopter pilots fly with night vision goggles at night.

As an aside: Police helicopters generally don't chase bad guys in ZERO visibility - but at night they can be flying in VFR while using heat-sensitive cameras to track the baddies.

In my experience as one of the people on the ground summoning such helicopters, they simply do not fly in IFR conditions. Based  on only one example I can recall, if conditions deteriorate while they're on the ground, they stay grounded and the medical personnel go with the patient by ambulance while the pilot stays with the helicopter at the scene. However, I'm sure these are all policies that will vary from one service to another.

If the helicopter is operating at an airport, it needs clearance like a regular flight, otherwise it would be a very dangerous situation for the helicopter and any other traffic in the area. Usually the ATC will give priority to the emergency helicopter (as much as possible), so it will leave the area without delay.
Regarding the weather conditions, there are two aspects that need to be considered:

The regulations allow emergency helicopters to fly VFR below VMC minima (this is true in Europe, I have no idea about FAA). So, an emergency helicopter, can continue VFR with visibility down to 1km, or even 800 meters for short periods of time.
If the helicopter is IFR equipped and the pilot(s) IFR rated, it can switch to IFR if necessary. On the way to the accident site this might not be very useful if the weather will not allow safe descent and switch to VFR, but on the way back to the airport/hospital, it can be very useful, provided the landing site has some kind of IFR procedure. Again, ATC will usually offer full cooperation in all this switching of plans and flight rules.

In the US, in controlled-airspace surface areas (i.e. not 10+ miles from an airport), both fixed- and rotary-wing aircraft may be granted a "Special VFR" clearance. This allows them to operate when the ceiling is below 1000' AGL and/or flight visibility is less than 3SM. For fixed-wing operations, flight visibility must be at least 1SM. Rotary-wing aircraft do not have this requirement.

I dont fly rotorcraft but I do interact with emergency choppers in 2 ways. I'll speak form what I have seen, I am in Philadelphia (PA, USA) so all my experience is with the procedures around here (FAA).
Storage And Takeoff:
I am currently doing my training at Northeast Philadelphia Airport (KPNE) where the local police and news choppers are stored (I think the medical choppers are there as well but I have yet to see them there). I have seen them depart often and generally they can get in the air and get out of the way so fast they don't interrupt normal aircraft traffic.
I have, on a few occasions, been instructed to extend my downwind for one of them to land or take off but again they are out so fast it's almost a non-issue. Keep in mind that KPNE is not Philly international so I don't know what its like at other cities and if they hold traffic for them. I would think they try to store the choppers at smaller airports near the city for this reason. Most major cities have a few airports anyway.
Landing At The Hospital:
My apartment happens to be next to one of the major hospitals in Philadelphia and I have the pleasure of looking right at the pad on the roof from my window. That being said I also have the "pleasure" of watching them practice and make approaches at the hospital. I can confirm that they have made landings (and frequently at that) in IFR conditions or even what seems below IFR minimums.
I would say in the time frame I am home (after 5pm every day) they make on average one landing every other day or more. If the weather is good, they will try and get more in, I would assume these are practice but I can't see the doors of the chopper so I can't be sure.
Bottom line is in my area the rescue choppers do fly IFR. I'll try and capture a picture today (it's very cloudy) if they are on approach.

Getting a clearance
If operating at a controlled aerodrome, a rescue helicopter needs a clearance just like any other aircraft. Given the quick response required, the crew will not be able to file a flightplan before the flight, so ATC does not know when a rescue flight is coming, or where it is going.
Where I work, the helicopter base has a panel with 4 buttons at the entrance to the hangar: North, East, South and West. When the helicopter is scrambled and the crew members are running to the hangar, they will press the button corresponding to the departure direction. This gives us a warning in the tower. Typically, from the time we get the warning and until they are ready for liftoff is somewhere between 2 and 5 minutes, and since we (roughly) know they departure direction, we can start planning other traffic around it (i.e. if they are departing to the north, they need to cross the runway - to the east or west they will fly through the approach path (depending on runway in use) - to the south, normally not an issue). I imagine other airport have similar systems in place, but even if we just have to wait for the pilot to call on the radio (sometimes they forget to press the button), that still gives us 30-60 seconds of notice before they are ready to go. ATC is used to dealing with rapidly changing and unexpected situations, and this is no different.
The rescue helicopter will almost always depart VFR, which is quite easy to handle from an ATC point of view. In case of bad weather (reduced visibility or low ceiling) we might need to provide additional separation to other traffic. Rescue helicopters have priority over almost all other air traffic (except emergencies and maybe a few other obscure cases), which means that we will always clear the rescue helicopter to fly in a straight line to where they need to go - regardless of normal procedures, noise abatement and other traffic. If another aircraft is in the way of the helicopter, we move that other aircaft. In your example with a 777 on final approach, it will be told to cancel approach/go around to make way for the helicopter. I have personally done so on more than one occasion, and when you tell the jet crew the reason, they don't mind at all. It's just like making room for an ambulance on the road.
VFR vs. IFR
As mentioned above, rescue helicopters will normally fly VFR. It's not that they can't fly IFR, but the problem is that landing at the rescue site (outside of an airport) cannot be done IFR, so it doesn't really make sense to fly there IFR. In case of low ceiling (clouds) forcing the crew to go IFR, they will have a problem when coming in to land: it will be impossible for them to descend VFR below the clouds. The way they typically deal with this is to fly to a nearby airport when an instrument approach (ILS etc.), fly that approach to below the clouds and then go VFR and continue to the rescue site. This detour is obviously not desired in a situations where seconds can mean the differences between life and death.
Rescue helicopters do have lower VMC minima than other flights, allowing them to fly VFR even when other flights would not be allowed due to visibility or ceiling. The advantage of helicopters is that they can fly really slow, so low visibility is not that much of an issue.
They do sometimes pick up IFR after having picked up a patient headed for the hospital, since some hospitals do have IFR approach procedures, or when returning to base after a mission. In my experience though, they will almost always fly VFR and if the weather is too poor to allow VFR, they will normally not be scrambled at all (since they would not be able to land at the rescue site). The exception is terrain following radar equipped radar helicopters that also have collision avoidance.

A good example of not flying in IFR conditions was at the F1 Eifle Grand Prix this fall (October?) at the Nurburgring in Germany. There were low clouds and rain off and on all day Friday. While conditions weren't bad at the track and the Medivac helicopter could have easily flown (the TV helicopter was up for most of the day), both practice sessions were cancelled because the helicopter could not land at the designated hospital because they were under IMC and they don't t have an IFR approach.

I don't fly rotocraft, but I can tell you if the airport is of any size they have to get a clearance unless they want to be turned into a hood ornament.
If the helicopter is pre-flighted and ready to go, it only takes few seconds to get a clearance, so it will not normally cause a delay.
Concerning IFR Flight: rotocraft require special equipment to fly IFR and it is much, much more dangerous than flying aircraft IFR because you are landing off field. Each operator and pilot have different policies, but in general police helicopters will rarely if ever fly IFR, and medivacs will only fly IFR if they judge it safe.
Note that flying at night is not the same thing as flying IFR. If the sky is clear it is VFR, even if it is night.
Being on a medivac crew is the most dangerous regular job in the United States and hundreds have died doing it.

In the UK at least, police ops are frequently IFR.  Any aircraft will only fly IFR if they judge it to be safe.

Related to IFR, I know that more than a few Formula 1 races (and, presumably, those in other race series), have been delayed because they require a helo for medical emergencies, and the weather is too bad to fly the chopper.

@FreeMan That's true, and varies a lot with jurisdiction, but being too bad to fly does not imply can't fly IFR.


text:
What is "Defense Area" on a VFR Sectional Chart?
What is "Defense Area" on a VFR Sectional Chart? The words "DEFENSE AREA" (in all caps) appear all along the US/Mexico border in blue. It's the biggest text on the chart. Interestingly enough, the same words don't seem to be along the US/Canada border.
Someone on airliners.net said this:

You're correct, there is a difference between a ADIZ and a Defense Area. A defense area is an area established on non-federal lands located within the United States, its possessions or territories, for the purpose of safeguarding classified defense information or protecting government equipment and/or material.
The establishment of a national defense area temporarily places such non-federal lands under the effective control of the Department of Defense and results only from an emergency event.
I am surprised that it is charted though, unless of course the government is getting ready for the flood of illegals coming to California to get drivers licenses and registering to vote.

That makes it sound like a ground thing, not an air thing. Then there's this, in the CFR 99.3:

Unless designated as an ADIZ, a Defense Area is any airspace of the United States in which the control of aircraft is required for reasons of national security.

And in the CFR 99.49:

All airspace of the United States is designated as Defense Area except that airspace already designated as Air Defense Identification Zone.

And in the AIM:

Defense Area means any airspace of the contiguous U.S. that is not an ADIZ in which the control of aircraft is required for reasons of national security.

So, what exactly is this Defense Area on my Sectional Chart and do I need to worry about it or think about it as I fly?
From the CFR 99.3 quote, what does this mean?

in which the control of aircraft is required for reasons of national security

Which sectional chart are you referring to, and could you describe it or help talk my eyes onto what specific area you are looking at?  I live in Washington state and fly off the Seattle sectional.  We have a coastal ADIZ and the Canadian border, but I can't picture what you are asking.  Thanks.

The term "defense area" doesn't appear in the FAA's Chart User's Guide. Can you give an actual example?

Hey, Michael. I live in Tacoma. Go to SkyVector.com and look along the Texas/Mexico border. There are several instances of the words "DEFENSE AREA" all along the US/Mexico border. It's the biggest text on the chart and is blue. You really can't miss it.

The FAR 99.49 quoted above was removed in 2004 and replaced by FAR 99.49

FAR 99.3 defines a Defense Area as an area in which air traffic can be controlled in the interest of national security. In other words, non-ADIZ airspace in which SCATANA or a similar plan can be implemented. In other words, all domestic airspace. It used to be clear that all airspace was Defense Area until FAR 99 got rewritten a couple of times in 2001-2004 when they were trying to figure out if the DC SFRA was an ADIZ. Now, the FAR that explicitly says that all non-ADIZ airspace is Defense Area is gone (to who knows where).
Nonetheless, all airspace that isn't an ADIZ is Defense Area, from sea to shining sea.
So why is it depicted on the southern border? To clarify that the airspace is not an ADIZ.

Take a look at this piece of the San Diego TAC. Notice how out in the ocean, the ADIZ is an actual 2-dimensional region. It's depicted with solid magenta lines with dots protecting the inside of the ADIZ. But at the beach, it devolves into a 1-dimensional line. But it's still depicted as the magenta line with dots. Look right there at the beach what has to happen, how the dots have to jump over the line. Thing is, since the ADIZ is a line there, the dots are actually outside of it, they can't protect the inside of it (since there is no inside to protect) and it looks like maybe all of California is an ADIZ, when it isn't. So the words DEFENSE AREA are printed there across the border from CONTIGUOUS US ADIZ to emphasize that the dots aren't actually protecting an ADIZ area; the ADIZ is too narrow to be correctly depicted.

Great answer, thanks for confirming!

What is a Defense Area?
A "Defense Area" is any area entirely surrounded by an ADIZ but not part of that ADIZ.  This is easier to understand with this older map:

Here you can see the Western Defense Area surrounded by the Pacific ADIZ, (part of) the Northern ADIZ, the Western ADIZ and (part of) the Southern Border ADIZ.  Likewise we can see the Eastern Defense Area surrounded by the Atlantic ADIZ, the Eastern ADIZ, (part of) the Northern ADIZ and (not shown) the Canadian ADIZ.
The Southern Border ADIZ was somewhat special (and challenging to chart) because it is zero-width, unlike the other ADIZes.
Notice that much of the Plains and Rockies are in the Central Open Area, which is not enclosed due to the lack of an ADIZ over the Gulf of Mexico.
In later years, there were several changes:

The Pacific ADIZ, Southern Border ADIZ, a new Gulf of Mexico ADIZ, and the Atlantic ADIZ were merged together into the Contiguous US ADIZ.
The Northern, Western, Eastern and Albuquerque ADIZes were eliminated.
The Alaska ADIZ was created.
The (eastern) Canada ADIZ was extended all the way from the East Coast around to Alaska.
A short (western) Canada ADIZ was created from Washington state to Alaska.
With ADIZes now completely encircling all of the Contiguous US, Canada and (most of) Alaska, that entire area became one big Defense Area, and the Central Open Area disappeared.

Note that the Alaska's western Aleutian Islands, Hawaii, Puerto Rico and various other island territories are not enclosed by an ADIZ and thus are still not part of a Defense Area.
What does this mean for pilots?
Aircraft crossing an ADIZ into a Defense Area are presumed hostile unless/until identified.  This means they must be on an IFR or DVFR flight plan, squawking a discrete transponder code and in contact with ATC/FSS.  If you are not, you will likely be intercepted by defense aircraft, either American or Canadian depending on which ADIZ it is, to ensure you're not a Soviet Russian bomber performing a sneak attack.  This is the original purpose of North American Aerospace Defense Command (NORAD), and why there are Canadians permanently stationed on a US military base.
In contrast, aircraft flying entirely within or leaving a Defense Area are presumed friendly, and you won't be intercepted unless you give them a specific reason to think you're hostile.  Reasons would include penetrating a Prohibited Area, a Restricted Area or the DC SFRA/FRZ without permission, or squawking 7500.  As a result, if you're VFR, you don't need to talk to ATC/FSS in class E/G airspace or (at least in the US) file a VFR flight plan at all.  Still, you should be aware of intercept procedures and monitor 121.5 if you're not talking to ATC/FSS, just in case.

How far away from the border does it extend? There are uncontrolled airports right on the border. What happens if you land there? "with slightly different rules" What rules?

How can his plane be searched without a warrant? If he didn't land coming from another country, how do they justify it? What's their probable cause?

@birdus FYI, I’ve replaced my answer as I’ve discovered the old one was incorrect. Please check it out and let me know if you have any questions.


text:
Light Plane: Transition to Right-Seat Flying: How to Prepare, What are Common Errors?
I'm preparing to start my CFI training and have almost exclusively logged all my time from the left seat of a Cessna 172 or 182. Is there a standard training program to transition to flying from the right seat? If not, how do people generally prepare, in an effort to make this less opinion-based, what are some common errors that pilots might make when learning to fly from the right seat?
Related: Is an approval required to fly from the right seat?

Are you asking what mistakes new instructors make in general, or what the difference is operating the controls from the right seat versus the left seat? In other words, is this INSTRUCTOR specific or are you asking about issues that would affect someone flying alone in the right seat?

@TylerDurden I guess I'm looking at both, instructor specific since I'm planning on being an instructor and also just general airmanship issues. I know the couple times I've flown from the right seat, my LH/RH muscle memory was something that caused some hiccups (left hand usually pulls yoke to go up, now pulling throttle with left hand reduces throttle (makes plane descend) or worse yet, pushing the right hand is used to giving more throttle, is now pushing the nose down with the yoke).  I guess anything that people do to help overcome those kinds of things.

It's super easy to fly from the right seat, and not worth worrying about. There may be some things you can't reach on the far left side of the panel, like the mags, but it's not much to worry about.

First, congratulations!  Earning a CFI certificate is a real undertaking.
For a literal textbook answer to your question I suggest opening this PTS pdf (assuming FAA CFI) and searching for "common errors" until you find yourself in relevant (to you) sections.  There are many examples.
On a personal note, I found that talking through every action made maneuvers go smoothly and let the instructor/examiner know that what I was doing is intentional.  It also forced me to follow my own directions so, since I knew what was supposed to happen, I just said it aloud and then did it.  It sounds silly but it worked well.
The transition to right seat flying is simple.  You'll have it down in an hour or two.  Nothing to it.  It's actually kind of anticlimactic.  Which plane are you using?


text:
Is the Suntoucher CG too far aft?
I acknowledge my very limited understanding of flight mechanics, but at first sight something tells me that the CG of the Suntoucher solar aircraft concept lies too far before the main wing and the forewing is too small to attain satisfactory stability and maneuverability.
This geometry is not OK at all.
Question:
Did I miss anything?

The Suntoucher Solar Aircraft concept:

References:

wordlessTech
designboom

Questions of the form, "This thing is crazy, amirite?" never do very well on SE sites because they typically need discussion rather than a single objective answer. If you're really interested in how stable the design is you might like to reword the question to be less judgemental.

To deal with your question directly, the span of the canard is much larger than normal, and I'd guess the engine is lighter than a typical piston, so the configuration doesn't look that unstable to me.

I think you miss two things: stability of canard configuration and purpose of the airplane. If the goal is to stay aloft during a long period describing large circles, maneuvrability requirements are not as important as energy efficiency (really small turn rates are acceptable)

A small forewing along with a shorter arm (Too advanced CG) may incur a serious penalty to the canard maneuvrability during the takeoff (Rotation). Likewise, a high AoA of the small forewing is required during flight for stability sake.

The engine might be lighter (negligeable) but the crew (2) not and that matters for the  balance. I assume the aircraft is lighter than the crew (I fly ultralight).

This aircraft is a conceptual design.  There is no real aircraft here.. move along folks: nothing to see here except rampant speculation.

Good catch! You are right, the center of gravity will be too much forward for a canard. If they put the prop on the sting behind the wing and the cockpit a bit ahead of the wing, things would look more credible.
The size of the foreplane is not obviously wrong, but the booms at the tips of the foreplane look strange. They serve no obvious purpose, like the sting, and the tailbooms look too thin for transmitting the loads from the vertical surfaces into the wing.
One third thing that looks odd are the control surfaces: The ailerons look too small to allow maneuvering in gusty weather at low speed. I guess the flaps on the inboard wing are for pitch control. Why are they not on the canard, where they would be more effective? Maybe because the center of gravity is so close to the foreplane, the designer decided to put them on the wing.
I agree with your assessment: This thing will remain an artist concept.
For comparison, see below a picture of a solar aircraft that actually flies and got most things right: The Icaré II:

Icaré II in flight (picture source)

Heh, most things... don´t let the design team in Stuttgart hear that ;-)

@yankeekilo: It is common knowledge that during development you collect a long wishlist of changes even before the plane flies the first time, and only a determined project leader will keep the engineers from tinkering and improving all the time. Only when the aircraft is certified do you have the knowledge to do it right the next time.

I was just kidding because I used to sit next-door to said team leader ;-)

The Suntoucher solar aircraft design looks fine to me. A key note: this is a solar electric powered aircraft using an AC electric motor to turn the prop.  Therefore the stinger section of the fuselage would contain batteries, adding much weight in the area of the wing, putting the CG near the prop on the wing side. Also with the prop mounted, and spinning on (around) the stinger part of the fuselage applying a pusher force on the crew pod, you need to strengthen the connection from the wing to the crew pod; thus the outriggers from the canards to the wing will carry the force and stabilize the wing

I think you are talking about the canards. Canard aircraft are much more common than you think and are certainly stable. For example, see this Rutan VariEze:

Image from airliners.net
(Static) stability means that the aircraft will return to its original position after a disturbance. For longitudinal stability (i.e. about the pitch axis), if some disturbance causes the aircraft angle of attack to increase, it should return t its original (lower) angle of attack by itself.
In case of the canard aircraft, the center of gravity is forward of the main wing.

Image from f-16.net
In this case, it is the main wing which is stabilizing. If for some reason, the angle of attack increases, the canard produces a moment about the c.g. that tends to increase the AoA. However, the wing also produces more lift (as AoA is higher), and this results in a stabilizing moment about the c.g.
The aircraft may still (most probably) remain a dream for various reasons, though I doubt having a canard has anything to do with it (Actually, the span is on the larger side). Without details, its just speculation.

Interestingly, the aircraft looks similar to the Rutan Voyager, which holds the world endurance record and had problems with pitch stability.

Image from nasa.gov